Extreme pressure lubricant



Patented June 24, 1941 UNITED STATES PATENT OFFICE 2,247,043 EXTREME PRESSURE LUBRICANT Henry G.

Woodbury, and Francis M. Seger, Pitman, assignors to Socony-Vacuum Oil Company, In-

Berger and Darwin E. Badertscher,

corporated, New York, N. Y., a corporation of New York No Drawing. Application September 25, 1940,

Serial No. 358,237

Claims.

This invention, which is a continuation in part of that disclosed inour copending application Serial No. 177,891, filed December 3, 1937, has to do in a general way with lubricant compositions and is more particularly concerned with hydrocarbon oil lubricants to which an agent has been added for the purpose of increasing the loadcarrying capacity of the lubricant.

As is well known to those familiar with the art, the ordinary type of hydrocarbon lubricant comprised only of a viscous petroleum fraction ucts disclosed in that application. The copend ing application discloses as typical specific examples of extreme pressure agents contemplated therein products obtained by reacting perchloromethylmercaptan with organic mercaptans and with alkali thiocarbonates. The present invention is directed to products obtained by reacting is incapable of withstanding the enormous pres- 'sures encountered between engaged surfaces in various types of machinery such as the hypoid gears used in motor vehicles. This fact has led to the development of the so-called extreme pressure lubricant, which is comprised of a suitable carrying medium such as a mineral oil and a minor proportion of addition agent which will provide or form between the engaged surfaces a lubricant film capable of withstanding these high pressures. Addition agents of the type referred to are known as extreme pressure agents or E. P. bases, and numerous materials have been proposed for such use. Among the various extreme pressure agents which havebeen produced and which have met with varying degrees of success are organic materials containing sulfur and chlorine. Our present invention relates to this general type of extreme pressure agent.

To demonstrate'the efficacy of a material as an extreme pressure agent, various laboratory tests have been developed, such tests employing,

apparatus having-relatively moving engaged surfaces associated with means for applying the lubricant thereto and associated with means for varying the load applied to the engaged surfaces. Typical tests for this purpose which have been accepted by the industry as providing an indication of the. performance of lubricants under extreme pressures are the Almen pin tests described by Wolf and Mougey, Proc. A. P. I. 1932, pages 118-130, and the S. A. E. test described in S. A. E. Journal 39, 23-4 (1936) Our aforesaid copending application Serial No. 177,891 carries a general disclosure of extreme pressure agents which are obtained by reacting perchloromethylmercaptan with organic compounds containing reactive hydrogen and organic compounds containing replaceable metal atoms.

The present invention relates to extreme pressure agents or reaction products falling within the general class of agents disclosed in the said copending application but being specifically different from the specific examples of reaction prodperchloromethylmercaptans with aromatic hydrocarbons.

Perchlorcmethylmercaptan is a chlorinated substituted sulfur chloride having the formula 08014 or ClsC-SCI. It can be prepared by .the chlorination of carbon disulfide accordingto the method of Helfrlchand Reid (Journ. Amer.

Chem- Soc. 43, 591 (1921)).- For example, carbon disulfide containing about 0.4 per cent by weight of iodine was chlorinated in the absence of direct sunlight at a temperature maintained below 25 C. until the volume of the reaction mixture had been doubled. This crude reaction product, yvhich contains carbon tetrachloride and sulfur chlorides in addition to the perchloromethylmercaptan, can, be used in the preparation of the lubricants contemplated by this invention, but it is preferable to purify the product by distillation on a water bath at C., followed'by steam distillation. Subsequent vacuum distillation of the material refined in this thalene, ethylnaphthalene, methylanthracene,

phenanthrene, diphenyl, etc.

In carrying out the reaction between the perchloromethylmercaptan and the aromatic hydrocarbon, the two reactants may be reacted directly or they may be reacted in the presence of a catalyst such as aluminum chloride which in some instances facilitates the reaction. Also, it

-may be desirable to employ a suitable solvent for the aromatic hydrocarbon.

Further details in the procedures which may be employed in synthesizing the reaction products contemplated herein may be obtained from the following specific examples describing the EXAMPLE ONE Reaction product of perchloromethylmercaptan and toluene A reaction mixture consisting of 50 parts by weight of perchloromethylmercaptan and an excess of toluene (203 parts by weight) and 39 parts by weight of aluminum chloride was prepared by dissolving the perchloromethylmercaptan in the toluene and adding the alumium chloride in small portions at room temperature. After the vigorous reaction had subsided, the mass was hydrolized by treatment with water. The toluene-soluble product. was water-washed, filtered and the excess of toluene distilled off. The residue was taken up in petroleum ether, filtered, and the filtrate distilled to remove the solvent. The product thus obtained was a viscous liquid with red-to-green fluorescence and practically no odor. A mineral oil blend containing per cent of this product failed in the S. A. -E. test at a load of 100 pounds at 1000 R. P. M. with at 14.6: 1 rubbing ratio and a loading'rate of 8.35 pounds per second. This same oil blend failed in the Almen pin test at a load of 16,000 pounds. The same oil without addition agent failed in the S. A. E. test at a load of 20 pounds and in the Almen pin test at a load of 3000 pounds.

EXAMPLE Two Reaction product of perchloromethylmercaptan solving 4'7 grams (0.25 mole) of perchloromethylmercaptan and 35 grams (0.27 .mole) of naphthalene in 200 cc. of petroleum ether, and after being cooled to C. the solution was treated with 40 grams (0.30 mole) of aluminum chloride. This reaction product was worked up as inExample One above to yield 32 grams of a dark brown liquid soluble in petroleum ether and 35 grams of a black asphalt-like product insoluble in petroleum ether but soluble in benzol. Mineral oil blends were prepared from both the petroleum ether-soluble product and the petroleum ether-insoluble product, such blends containing 5- per cent of the representative products in the same blank mineral oil used in the tests described in Example One. The blend containing 5 percent of the petroleum ether-soluble product'passed the S. A. E. test at a load of 560+ pounds and passed the Almen pin test at a load of 30,000 pounds. Theblend' saturated with 5 per cent) the product which was insoluble in petroleum ether failed in the S. A. E. test at a load of pounds and the Almen pin test at a load of 9000 pounds.

EXAMPLE THREE Reaction product of perchloromethylmercaptan and tetralin (tetrahydronaphthalene) This reaction mixture was prepared by dissolving 93 grams (0.50 mole) of perchloromethylmercaptan and 33 grams (0.25 mole) of tetralin in 200 cc. of petroleum ether. The solution was cooled to 10 C. and treated with 39 rams (0.29 mole) of aluminum chloride. The mixture was then allowed to warm up to room soluble'product failed in the S. A. E.

'130 C. at atmospheric pressure and then for 'pin test at a load of 9.0 pounds.

above. The excess perchloromethylmercaptan remaining in the petroleum ether-soluble fraction was removed by topping to a final liquid or pot temperature of 153 C. at millimeters pressure. This gave 36 grams of a petroleum ether-soluble product in the form of a deep red, very viscous oil. There was also 22 grams of a solid product insoluble in petroleum ether. A 5 per cent mineral oil blend of the petroleum ether -soluble product failed in the S. A. E. test at a load of ,240 pounds and passed the Almen pin test at a load of 30,000 pounds. A mineral oil blend saturated 5 per cent) with the petroleum ether-insoluble product failed in the S. A. E. test at 80 pounds and the Almen pin test at 4000 pounds.

EXAMPLE Form Reaction product of perchloromethylmercaptan and xylene This reaction mixture was prepared by dissolving 37 grams (0.2 mole) of perchloromethylmercaptan and 22 grams (0.2 mole) of xylene in 200 cc. of petroleum ether. The mixture was cooled to 10 C. and was then treated with 28 grams (0.2 mole) of aluminum chlorid by gradual addition of the aluminum chloride over a periodv of about 28 minutes. The reaction mixture was hydrolized and worked up as in Example One above and yielded a petroleum ethersoluble product consisting of a dark-colored viscous liquid, and a petroleum ether-insoluble product consisting of a black, tarry residue. A 5 per cent solution of the petroleum ether-soluble product in mineral oil failed in the S. A. E. test at a load of 350 pounds, and this same oil blend failed in the Almen pin test at a load of 28,000 pounds. A 5 per cent mineral oil blend of the petroleum ether-insoluble product failed in the S. A. E. test at a load of pounds and the Almen pin test at a load of 17,000 pounds.

EXAMPLE FIVE Reaction product of perchloromethylptercaptan and fluorene This reaction was carried out by mixing'together 46.5 grams (0.25 mole) of perchloromethylmercaptan and 41.5 grams (0.25 mole) of fluorene and heating the mixture for a period of 6 hours at a temperature of from to /2 hour at a temperature of C. under a vacuum of about 30 millimeters. The total loss of volatile material by this treatment was equal to approximately 0.25 mole of HCl, and the final heat treatment under vacuum showed no evidence of unreacted perchloromethylmercaptan remaining. The residue in the flask was first dissolved in benz'ol. and then filtered and the benzol distilled ofl.. This product yielded a petroleum ether-soluble .fraction and a petroleum etherinsoluble portion, which were blended with mineral oil and tested as ln'the foregoing examples.

A mineral oil blend containing 5 per cent of the petroleum ether-soluble portion failed in the S. A. E. test at a load of 320 pounds and the Almen The 5 per cent mineral oil blend of the petroleum ethertest at a load of 20 pounds but in the Almen pin test went to a load of 10,000 pounds before failure.

The reaction products contemplated herein may be blended with mineral e11 fractions in amounts varying from 0.5 per cent to 20 per cent 'to provide lubricants of improved oiliness and load-carrying capacity. It is to be understood that while we have herein described specific r e-.

action conditions and proportions and specific aromatic hydrocarbons for obtaining the reaction products contemplated, such specific de.--

tails and specific reactants are merely for illustrative purposes.

We claim:-

1. An extreme pressure lubricant comprising a hydrocarbon lubricating oil and in admixture therewith a minor proportion of the product obtained by the reaction of perchloromethylmercaptan with an aromatic hydrocarbon. I

2. An extreme pressure lub 'cant'comprising a hydrocarbon lubricating oil and in admixture c. therewith a minor proportion of the product obtained by reacting perchloromethylmercaptan with an aromatic hydrocarbon in the presence of aluminum chloride. l

3. .An extreme pressure lubricant comprising a per cent to about 20 percent, of the product obtained by the reaction of perchloromiethylmercaptan with an aromatic hydrocarbon.

4. An extreme pressure lubricant comprising a hydrocarbon lubricating oil and in admixture therewith a minor proportion of the product obtained by the reaction of perchloromethylmercaptan with an aromatic hydrocarbon, said reaction product beingpresent in an amount suifwith an aromatichydrocarbon selected from, the group consisting of toluene, xylene, naphthalene,

20 tetraliri, and fluorene.

HENRY G. BERGER. DARWIN E. BADERTSCHER.. FRANCIS M. SEGER.

. 3' hydrocarbon lubricating oil and in admixture therewith a minor proportion, fromabout 0.5- 

